There is a lot of confusion about Burchell’s
Zebra, Quagga and other zebras, despite there being only
three zebra species.
The reason for this is in the history
of zebra descriptions and naming. Whenever an early explorer
took a zebra skin from Africa to Europe, it did not match
any of those in collections, so, it "needed a name".
That there is enormous individual variation
in, especially, the Plains Zebra (which is often refered
to as Burchell’s Zebra), had not been expected nor
realized until the early 1900’s. By then, the Quagga,
which had been described and named in 1788, had become
extinct. The Burchell’s Zebra, described and named
in 1824, was still around.
Gradually, further north, somewhat more extensively-striped
zebra populations became known. It was noticed that they
were very similar to Burchell’s Zebra, and they
were described and named as subspecies of Burchell’s
Zebra. These subspecies were usually given names of explorers,
like Chapman, Wahlberg, Selous, Grant, Boehm, etc. Eventually
the zebra population from which William Burchell had taken
a skin to the British Museum, had been wiped out, but
"Burchell’s Zebra subspecies" continue
to exist in many areas of Africa.
Now I must explain why I prefer to speak of Plains Zebra,
rather than Burchell’s Zebra, as is often done.
The original Burchell’s Zebra (sometimes refered
to as the "true" Burchell’s Zebra) is,
or rather was, one of the subspecies of the species under
discussion. Consequently, all the other subspecies (with
explorers’ names) should be called Chapman’s
Burchell’s Zebra, Wahlberg’s Burchell’s
Zebra, Selous’s Burchell’s Zebra, and the
"extinct" subspecies burchelli should be called
Burchell’s Burchell’s Zebra. This would be
ridiculous. Because the species that we are discussing
here, lives on the plains, in contrast to the Mountain
Zebra, which prefers mountainous terrain, the term "Plains
Zebra" for the species as a whole, with its various
subspecies (and there is no agreement among scientists
how many "subspecies" there are), is a much
more sensible term than Burchell’s Zebra. Fortunately
this usage seems to be favoured more and more. It will
certainly gradually eliminate the enormous confusion that
it was realized that there are far too many names for zebras,
and many were consequently made synonyms, the Quagga was
no longer there. How it was related to the other zebras,
was not certain. So, one left it as a species (as it had
been described, after all), and called the few zebra subspecies
that live on the plains, "Burchell’s Zebras".
Then there was, of course, the Mountain
Zebra, and, in East Africa, the Grevy Zebra. Three living
zebra species, and one extinct "species"? No one
was certain about this. Some scientists tended to see the
Quagga as a subspecies, others as a species. What is more,
it was thought that the question about the Quagga’s
taxonomic position could no longer be answered, because
there were no more Quaggas around to be studied.
But then, in the early 1980’s, to
everybody’s surprise, that question WAS answered,
through the analysing of the Quagga’s DNA from tissue
that was removed during the remounting of several of the
stuffed original Quaggas in museums.
These developments are fairly new, and
the results of the Quagga DNA analysis, namely that the
Quagga WAS one of the Plains Zebra subspecies, not a species
of its own, have not yet been absorbed everywhere, especially
where people are not involved in Equid taxonomy.
Now, was the Quagga a subspecies of Burchell’s
Zebra, or the other way around? That is simple, because
if it is established that two former species names in fact
refer to one and the same species, then the older of the
two names takes precedence over the younger.
Equus quagga ---1788, Equus burchelli ---1824.
All plains zebras therefore, including
the Quagga and the "true" Burchell’s Zebra
(as it is sometimes called) are subspecies of Equus quagga.
The Quagga’s full name is Equus quagga quagga; its
immediate northern cousin was Equus quagga burchelli; the
next subspecies in a northerly direction presently is Equus
quagga antiquorum, etc.